Combined Effect of Refrigeration and Modified Atmosphere Packaging on the Shelf Life of Ready-to-Serve Pizza: Biochemical and Sensory Attributes

摘要

This study evaluated the combined effect of Modified Atmosphere Packaging (MAP) and refrigeration (7±1°C) on shelf-life extension of ready-to-serve pizza. Quality assessment was based on sensory and biochemical indices determination. The gaseous atmospheres used were: atm1: air (control); atm2: 100% CO₂, atm3: 100% N₂ and atm4: 50% CO₂/50% N₂. Moisture content, water activity, pH, titratable acidity, free fatty acid s, peroxide value, thiobarbit uric acid , tyrosine content, lycopene content, color profile (L*= lightness of the product; a*= redness of the product; b*= yellowness of the product; total color difference; relative yellowness) were monitored. Sampling was carried out at predetermined time intervals namely 0, 15, 30, 45 and 60 days. The results indicated that MAP with 100% CO₂ more significantly inhibited the lipolytic oxidation, reduced proteolysis, effectively prevented total acidity (less decrease in pH) and have preservative effect on color indices and hence extended shelf life than did other treatments. Results of the present study show that the limit of sensory acceptability was only reached for the aerobically stored samples somewhat before days 15 of storage. The shelf life of baked pizza samples in conventional air packages was 15 days. However, a significant shelf life increase of 45 days (300% increase) was achieved under modified atmospheres for baked pizza samples.